Golfing is a popular sport which is now played throughout the world. Putting has been recognized as one of the most difficult aspects of the game and accounts for nearly half of a golfer's score. It is generally recognized that putting causes more anxiety among golfers than any other aspect of the game. While most approach shots offer an opportunity of recovery, every missed putt adds a stroke to the score and no amount of skillful follow up can change that. The following statistics collected from PGA tour professional scores during tournament play indicate the difficulty which putting poses:
______________________________________ Length of Putt Successful Putts ______________________________________ 6 feet 45-55% 10 feet 15-30% 15 feet 10-22% 20 feet 6-16% 25+ feet 10% ______________________________________
For putts over 25 feet, the percentage of success declines as the length of the putt increases.
When professionals who practice constantly have so little success at putting, it is no wonder that ordinary golfers often consider putting a frustrating exercise. The following patents are known to relate to various inventions directed to improving golfers' performance:
U.S. Pat. No. 3,188,086--Parmley
U.S. Pat. No. 3,170,690--Goranson et al
U.S. Pat. No. 2,132,219--Pirie
U.S. Pat. No. 1,616,377--Knight
U.S. Pat. No. 1,561,349--Murphy et al
U.S. Pat. No. 1,618,638--Coles
U.S. Pat. No. 1,684,192--Nemeth
U.S. Pat. No. 2,706,635--Thomas
U.S. Pat. No. 4,491,323--Kozub
G.B. 522,814--Cottingham
The applicant's U.S. Pat. No. 4,880,240 which issued Nov. 14, 1989 also relates to an apparatus for improving a golfer's putting stroke. While this apparatus represents an advance in the art, subsequent experimentation and experience has shown that the apparatus can be further improved.
It is a well known principle that the shaft length of a putter should enable a golfer's arms to hang comfortably when their eyes are directly over the ball. If the putter is too short, the golfer will stand too close to the ball and their eyes will be outside a target line which lies under the center of the ball. If the putter shaft is too long, it forces the golfer away from the ball and their eyes are inside the target line.
There are three principal factors which affect the mechanics of putting. Those factors include:
1) Putter Path. The proper path for the putter is a straight back and straight forward stroke along the target line. Any deviation from the target line at the impact zone will transmit into a deviation in the roll of the ball. On a 10' (3.3 m) putt, striking the ball with a putter moving five degrees off line results in missing the cup by 2" (5 cm). Although most beginners cannot detect five degrees of misalignment at the impact zone, the results are noticeably detectable.
2) Face Angle. When a putter impacts a golf ball, the face of the putter must be at right angles to the target line. If the face of the putter is not square to the target line, 90% of the deviation is translated into a deviation in the roll of the ball. For a 10' (3.3 m)putt, if the face of the putter is skewed by five degrees, the ball will miss the hole by about 9" (22.5 cm).
3) Impact Point. For every putter, there is an ideal point of impact on the face of the putter. This point is commonly referred to as the "sweet spot". If a stroke misses the "sweet spot" by a quarter of an inch (0.6 cm), 95% of the error is transferred to the movement of the ball. That error translation is enough to cause the ball to miss the cup on any putt which is more than 8' (2.6 m) in length. The farther away from the impact zone that the ball is struck, the more deviation is translated to the path of the ball.
Most golfers, especially beginning golfers, find it difficult if not impossible to coordinate the putter path, the face angle, and the impact point while attempting to judge the required force to sink a putt. As a result, many golfers find putting a frustrating and unsatisfying activity which is never fully mastered. There therefore exists a need for a simple apparatus which permits a golfer to concentrate on the best target line and the speed of a green while his or her body "learns" the muscle movements required to control putter path, face angle and impact point.
A recent development in golf putting is the use of extra long putters (up to 52" (132 cm)) in a technique known as the "pendulum stroke". The pendulum stroke involves gripping the top of a long putter shaft in one hand steadied against the chest and swinging the putter in a pendulum action with the other hand. This is believed to lessen the control required of the short muscles in the wrists and hands for a traditional putting stroke.
One problem with extra long putters is that they do not fit properly into a golf bag. Such putters are therefore difficult to handle when not in play. Telescoping putter shafts have been developed to overcome this problem but telescoping shafts are expensive to manufacture and unstable if not well made. There therefore exists a need for an inexpensive removable extension for use with a putter of normal length which permits the putter to be used for pendulum stroke putting.